Television apparatus



Patented Oct. 10, 1933 ,UNITEDY STATESg lI5ATENT; oFF-ics '1,930,071 TELEVISION ArPARA'rUs Fritz Banneitz, Charlottenburg, near-Berlin, and

Georg Schubert, Siemensstadt, near Berlin, Germany, assignors tothe firm of Fernseh Aktien-Gesellschaft, Zehlendorf, near Berlin,

Germany Application April s, V193,2, serial Norofaozz,

and in Germany April `10, 1931-I the more difficult to full, the greater the diameter ofthe disc, particularly when the latter is made of thin metal sheet, which however is necessaryif the inertia is toy be kept low.

It has been found by experimentlthat discs, "particularly discs of large diameter and high speed of rotation, run steadily if they are made in the form of a spoked wheel, or are holed, meaning that between a boss portionand a rim portion parts of the material of the disc are re- Disadvantages occur, however,A even with these discs because, due to slight and generally unavoidable strain caused during running by the resistance of the air, the thin spokes of such wheels readily set themselves somewhat transversely, thereby producing fluttering of the disc and, above all, very unpleasant noises.

These defects are obviated according to the invention by the arrangement to be described Vhereinafter'. The essential feature of the invention resides in the provision on either side of the spoked wheel of solid discs of light material, for example thin sheet metal, presspahn, pertinax, cardboard or stout paper, having a radius smaller than, equal to or larger than the radius of the spokes. These auxiliary discs are firmly clamped with the Nipkow disc on the spindle, but they are not otherwise connected to it at any point. Since the auxiliary discs are not rigid, they do not bear against the Nipkow disc in the position of rest, but stand out far away from it. They only bear against the Nipkow disc during rotation and then only to an extent depending upon their resiliency and the centrifugal force or the currents of air which are set up.

During rotation of this combination of discs, the air between the auxiliary discs is also set in rotation by friction against the auxiliary discs VYand at the same time it is forced outwardly. The

uresult of this is, in the first place, that the air between the two auxiliary discs moves in the same direction as the Nipkow disc, so that the spokes of the Nipkow disc are substantially at rest rela- A tively to the air rotating with them. In the second place, however, clue to the air being forced outwardly and the partial vacuum produced thereby, the auxiliary discs lbear against the Nipkow disc, thus preventing the three discs from gaping apart at the edge. It has been found by experience that it is occasionally preferable to insert between the auxiliary discs and the Nip- .kow'disc small distance discs of slight thickness madeof resilientmaterial, for example rubber, thereby forming a certain air space round the Nipkow disc. The'air space formed during rota- 3g" tion, however, should not be` too large in the axial direction. 'Ihe effect desired'according to the-invention is' best obtained when the said air space isquite small, for instance of the order of ymagnitude of the thickness ofthe' sheet metal 7' of the Nipkow disc. Y

If distance rings are not inserted between the auxiliary discs and Nipkow disc, the auxiliary discs, particularlywhen they are made of Very thin material, for example paper, bear too hard against the Nipkow disc, due to the reduced air pressure,-and the disadvantages of va solid discV` readily make their appearance (for example, the disc starts to wobble) ,which is justwhat the cutout portions are intended to obviate. It is now ,90'A possible to obviate this disadvantage by the insertion of the intermediate discs without therebyA impairing the advantages of the auxiliary discs.

In brief, the essential feature of the invention does not consist of, say, firmly clamping the Nipkow disc by-or with the two auxiliary discs, as in clamping circular saws, polishing wheels, grindstones, etc., but of forming an air space round the portion of the Nipkowdisc which is not employed for picture scanning or composing, the relative velocity of the said air space being very small in comparison with the rotating Nipkow disc.

Of course, the principle of the invention is not limited to holed discs, but it also provides certain improvements in the case of solid discs, sinceV the bulges or other irregularities of the discs do not then have such aconsiderable effect.

Figure 1 of the accompanying drawing shows in section a disc arrangement based on the prin- 16h ciple of the invention, and

Figure 2 the same arrangement in elevation.

The holed Nipkow disc 1 with the spokes 2, 2 2, etc. is secured together with the two solid auxiliary discs 3 and 4 andthe distance discs 5 105 and 6 on the hubv 7 by means of the nut 8. The hubV with the discs rmly clamped on it is, in its turn, fixed to the shaft 9 by known methods.

Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim is:-

1. In a television system, a Nipkow-disc and an auxiliary disc of smaller diameter on each side thereof in axially spaced relationto form a relatively narrow air space between said Nipkow-disc and each auxiliary disc. A

2. In a television system, a Nipkow-disc and an auxiliary disc of smaller diameter on each side thereof adapted to rotate with the same speedras said Nipkow-disc, said auxiliary discs being axially spaced from said Nipkow-dise to form anarrow air space therebetween 3. In a television systemfa NipkoW-disc and an auxiliary disc of smaller diameter on each side thereof in axially spaced relation to form a narrow air space between said Nipkow-disc and each auxiliary disc, said auxiliary discs being formed' of thin resilient material and being adapted to bear against the sides of said Nipkow-disc`during the rotation thereof. y 4. Ina television system, a Nipkow-disc and an auxiliary disc of smaller diameter on each side thereof adapted to rotate with the same speed Das said Nipkow-disc, lsaid auxiliary discsbeing axially spaced from said Nipkow-disc to form a narrow air. space therebetween, said auxiliary Y discsbeing formed of thin resilient material and being adapted to bear against uthe sides of said -Nipkow-disc during the rotation thereof.

` 5.v In combination with a Nipkow-disc provided with apertures to form spokes inthe body of said disc, two solid auxiliary discs,one on each side of said Nipkow-disc and axially spaced therefrom -.to form a narrowair space between said Nipkowl disc and each of said auxiliarydiscs, said auxiliary discs having a smaller diameter than-said Nipkow-disc and adapted to cover the spokes formed in the body of saidV Nipkow-disc.

4Q 6. In combination with a Nipkow-disc provided with apertures to formuspokes in the body of said disc, two solid auxiliary discs, one on each side of said NipkoW-disc and axially spaced therefrom to form a narrow air space between said Nipkow- 453 disc and each of said auxiliary discs, said auxiliary discs being of a diameter to cover the spokes formed in the body of said NipkoW-disc, said auxiliary discs being formed of thin resilient material and being adapted tobear against the sides of said Nipkow-disc .during the rotation thereof.

7. In a television system, a Nipkow-disc having von each side a solid auxiliary disc of smaller diameter, means for forming a narrow air space `between Vsaid Nipkow-disc and said auxiliary Vfixedly secured to said shaft adjacent opposite sides of said NipkoW-disc and being axially spaced therefrom to form a narrow air space between' said Nipkow-disc and each auxiliary disc.

10. In Vcombinatonwith a Nipkow-disc on a rotatable shaft, two solid auxiliary discs of smaller diameter, and means on said shaft and positioned between said-Nipkow-disc and each auxili'ary discfor forminga narrow air space between said discs. Y Y

11. In combination with a Nipkow-disc on a rotatable shaft, two solid auxiliary discs of smaller diameter, and means `on said shaft and positioned between said Nipkow-disc and each auxiliary disc for `forming a narrow air space between said discs, said auxiliary discs being fixedly secured on saidshaft and being formed of thinY resilient material and being adapted to bear against the sides of said Nipkow-disc during the rotation thereof. I

FRrrz BANNEIT?.V GEORG SCHUBERT. 

